JPS5989186A - Small type printer - Google Patents

Abstract

PURPOSE:To provide an inexpensive type wheel selecting type printer capable of controlling a part corresponding to the whole digit places by a number of electromagnets which number is smaller than the number of digit places, wherein a selecting pawl member corresponding to a non-selected digit place is driven by a selecting pawl controlling means, and is engaged to a type wheel for the digit place to stop the type wheel. CONSTITUTION:When a selecting pawl 4 is driven by an electromagnet 5 through an attracting plate 6, the pawl 4 receives a driving force until a tip part 401 thereof enters into the locus of a toothed part 202 of the type wheel 2 so that it can stop the type wheel 2. Accordingly, the type wheel 2 is securely stopped, and erroneous actions due to external disturbances such as frictional loads can be prevented from occurring. A stand-by position of the attracting plate 6 is determined by the position where a projected part 601 of the plate 6 collides against a colliding part 802 of a rigid positioning plate 8 fixed to a frame 21, and the gap between the plate 6 and the electromagnet 5 is not further enlarged, so that stable capability can be constantly obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a type wheel selection type compact printer, and relates to a device for controlling a plurality of type wheels with a single electromagnet.

A mechanism in which the number of electromagnets in a conventional small-sized printer is reduced by an order of magnitude is disclosed in Japanese Patent Application Laid-Open No. 16228/1983. According to Japanese Patent Application Laid-Open No. 54-16228, in order for the rigger lever to engage with the ratchet pawl of the type wheel and stop the type wheel, it must further rotate by inertia after being driven by the armature lever, and the trigger lever The rotational speed also fluctuates due to disturbances such as fluctuations in the frictional load applied to the printer, leading to the risk of malfunctions such as incorrect selection of type. Also, when the second type wheel enters the second rotation from the first rotation, the second trigger lever has to go over a part of the stopper of the type wheel, so the cam that controls the position of the trigger lever has a three-stage diameter. However, due to its mechanism, its diameter cannot be made very large, it is difficult to control accuracy, and its operation is complicated. Also, when the first type wheel is selected, two trigger levers are driven by electromagnets, whereas when the second type wheel is selected, only one trigger lever is driven if the first type wheel is selected. Often, if the first type wheel is not selected, two wheels must be driven, and the first trigger lever is also subjected to a frictional load with part of the stopper of the type wheel, reducing the load on the electromagnet. This was large and the fluctuations were large, and the cost of creating an electromagnet with sufficient capacity for this was high and was a waste of design. In addition, the standby position of the armature lever is determined by the position where it contacts the spring stopper, and slight deformation of the spring stopper can cause the gap between the armature lever and the electromagnet suction part to fluctuate, making the electromagnet's performance unstable and causing malfunctions. There were drawbacks such as:

The present invention eliminates such drawbacks, and its purpose is to provide an inexpensive, small-sized printer that can control all digits with fewer electromagnets than the number of digits, and also has a stable selection claw operation and high reliability. There is a particular thing.

The main feature of the present invention is that the selection pawl control means drives the selection pawl member of the unselected digit and engages and locks the type wheel of that digit, and furthermore, the selection pawl control means and the selection pawl member The engaging structure is characterized by a structure that prevents malfunctions even when returning the selection claw member to the standby position.

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a side sectional view showing the main parts of an embodiment of the present invention;
The figure is a schematic front view showing the arrangement of the main parts of the selection mechanism, FIG. 6 is a perspective view of this embodiment, and FIG. 4 is a timing chart showing the operation of the main parts of this embodiment. 1 is a type wheel spindle and has a groove 101. 2 is a type wheel, which is supported on the type wheel shaft 1, and has type 201 on its outer periphery, and selection teeth 202, grooves 206, protrusions 204, and recesses 2 on its side surfaces.
05 is provided. 3 is a type ring spring, and the convex roller 01 at one end engages with @101 of the type wheel shaft 1, and the convex portion 502 of η^1 is reached by a groove 203 provided in the type wheel 2. , has spring properties. 4 is a selection pawl whose tip 401 engages with the teeth 202 of the type wheel 2 to selectively arrange predetermined type 201 at the printing position 20, and has a stepped portion 402, a protrusion 4'03, and elongated holes 404 and 405. are doing. The four odd-numbered selection claws and the even-numbered selection claw 4B have different shapes, and the even-numbered selection claw 4B further has a stepped portion 406.

In addition, from now on, the subscript A will represent the odd-numbered part side, and the subscript B will represent the part with (+% number' digits),
Use only when specifically necessary. Even number digit selection claw 4
B engages with the four parts 205 of the even-numbered type wheel 2B and has the function of locking the even-numbered type type wheel 2B so that it does not rotate. The type wheel 2 and the type wheel 3 and selection claws 4 are arranged in the number of digits. 5 is an electromagnet, and 6 is attracted by the electromagnet 5 in the direction of the arrow force, and the protrusion 403 of the selection claw 4. It is a suction plate that engages with the selection pawl 4 and drives the selection pawl 4 in the direction of engagement with the tooth portion 202 of the type wheel 2, and is roughly dogleg-shaped and has a convex portion 601. The electromagnets 5 and the suction plates 6 are arranged at a ratio of one in every two digits, so the number is half of the number of digits. 7 is pivotally supported by a selection pawl control lever shaft 19 fixed to the frame 21 and rotates in the upward direction of the arrow, and its driving portion 701 drives the selection pawl 4B of even number digits to engage with the recess 205 of the type wheel 2B of even number digits. 8 is a positioning plate fixed to the frame 21; 8 is a positioning plate fixed to the frame 21; When the stepped portion 402 of the selection claw 4 comes into contact with the positioning portion 801, the position shown by the solid line in FIG. is called the selection position (the symbol is already shown), and the convex part 601 of the suction plate O is positioned at the contact part 802.
When they come into contact with each other, the suction plate O hits. Reference numeral 9 denotes a selection pawl shaft which is fixed to the frame 21 and pivotally supports the selection pawl 4 and the g&drawing plate 6 arranged as shown in FIG. Reference numeral 1° denotes a selection pawl spring, which applies a force to rotate the selection pawl 4 counterclockwise in FIG. 1 about the selection pawl shaft 9 and a force to lower it downward. Reference numeral 11 designates an electromagnet mounting plate which is fixed to the frame 21 and is used to attach the electromagnet 5 and the selection claw spring 10. 12 prints the printed characters 201 aligned at the printing position 20 on the printing paper 1.
5 and an ink ribbon 16 at the same time to print. 16 is a paper feed roller that feeds the printing paper 15 by a predetermined amount by rotating in the direction of the arrow;
is a paper press roller that presses the printing paper 15 against the paper feed roller 16. Reference numeral 17 denotes a cam gear which is pivotally supported on a fixed cam gear shaft 18 of the frame 21K, rotates once per printing cycle, and drives the selection pawl control lever 7 by a grooved cam provided on the side surface.

Next, the operation of the printing apparatus having the above configuration will be explained.

First, in the character selection process, when a print command is received, the motor (not shown) starts rotating and the train wheel system (not shown) is interlocked. The selection pawl is controlled by the grooved cam of the cam gear 17 provided on the train string, and the bar 7 rotates in the direction of arrow K from the state of 7σ to the state of 7c, and the selection pawl 4B of even number digits is changed from the state of 4Ba to the state of 4Ba. drive, and the tip part 401B prints @
2 and locks the type ring 2. At this time, the selection claw 4 has a long opening, so the lower part 405B
is driven to position C without contacting the selection claw shaft 9. Note that FIG. 6 shows the states of 7c and 4B. Of course, in this state, only the type wheels 2B of even number digits are locked, and the two type wheels of odd number digits can rotate freely. In this state, the type wheel shaft 1 begins to rotate in the direction of arrow A, but the type wheels 2B of even number digits are stopped by the selection claws 4B of even number digits and do not rotate. The two type wheels with odd number digits are the type wheel axis 1, 11.
It rotates together with the type wheel shaft 1 due to the frictional force of the type ring spring 3 engaged with 'i' l 01. Type wheel spindle 1 has type 20
It is equipped with a detection device that detects the position of 1, and generates a timing pulse as it rotates. When the desired printed character 201 comes just before the printing position 20, the electromagnet 5 is energized in synchronization with the timing pulse (the fourth timing pulse in FIG. 4), and the suction plate 6 is attracted in the direction of the arrow force (FIG. 4 f). do. At this time, the suction plate 6 is a projection 40 provided on the selection claw 4A of odd number digits.
3A, drives the odd-numbered digit selection claw 4A from the state 4Aα to the state 4A6, and engages the tip 401A with the tooth portion 202 corresponding to the desired printed character 201, thereby selecting the desired printed character 201. is locked at the printing position 20. At this time, the even-numbered selection pawl 4B has already been driven to the 4BG position by the selection pawl control lever 7, and its protrusion 40
3B is also at the position 405Bc, the suction plate 6 engages only the projections 403A of the selection claws 4A of odd number digits, and therefore the suction plate 6 drives only the selection claws 4A of odd number digits. Further, the driven selection claw 4Ab has a stepped portion 402Ab.
and the positioning part 801 of the positioning plate 8 are in contact with each other as shown by the dashed line in FIG. The fall is also stopped and it is positioned at the position indicated by the symbol. In this way, when the type wheel shaft 1 rotates approximately one revolution, the selection process for odd numbered digits is completed, but only for odd numbered digits in which the type 201 is not selected, the selection pawl 4A is engaged with the last tooth 202. do.

At this time, the electromagnet 5 is energized in synchronization with the 14th timing pulse in FIG. 4 (FIG. 4, 2). This last tooth part 2
Since 02 corresponds to a location where the type 201 is not provided, nothing will be printed even if the selection claw 4A is engaged. By driving all the selection claws 4A of odd number digits to the selection position in this way, when the electromagnet 5 is energized in the next even number digit selection process, the selection claws 4 that are driven via the suction plate 6 will be moved to the even number digits. Only the selection claw 4B is required, and the electromagnet 5 always drives only one suction plate 6 and one selection claw 4.

become.

When the type wheel shaft 1 makes approximately one rotation and the selection process for the odd number digits is completed, the convex portion 301 of the type ring spring 3 attached to the type wheel 2B of the even number digit falls into the groove 101 of the type wheel shaft 1 again, and the type wheel shaft 1 is rotated. 1 will stop for a while. This is section e shown in FIG. During this time, the selection pawl control lever 7 is rotated in the direction of the arrow by the grooved cam of the cam gear 17.
Avenge 45 to the 1st rank of a.

Since the selection pawls 4B of even number digits are applied with force in the counterclockwise rotation direction and downward direction in FIG. At this time, the suction plate 6, which is no longer receiving the suction force from the electromagnet 5, may vibrate in the rotational direction around the selection pawl shaft 9. At this time, when the even-numbered selection pawl 4B is returned, its protrusion 406B collides with the suction plate 6 and receives a force that rotates the selection claw Rqi+ 9 in the clockwise direction in FIG. There is a concern that it will not be able to return to 4Ba and will fall directly to the selection position 4Bb, leading to malfunction, but in the present invention, even number digit selection claw 4
The engagement surface between the stepped portion 406 of B and the drive portion 7D1 of the selection pawl control lever 7 has an angle as shown in FIG. 1 with respect to the force that attempts to rotate the selection pawl 4B clockwise. The angle of this engagement surface and the selection claw are adjusted so that a frictional force sufficient to prevent the selection claw 4B from disengaging with the selection claw control lever 7 even if the selection claw 4B receives such a force is applied to this engagement surface. Spring 1
Since the spring force of 0 is determined, the selection claw 4B can reliably return to the standby position, and there is no fear of malfunction as described above.

When the selection pawl control lever 7 returns and the type wheel set 1 starts rotating again in the direction of arrow A, the type wheel 2B of even number digits rotates the type wheel set 1 due to the frictional force between the type ring spring 3 and the groove 101 of the type wheel set 1. begins to rotate in sync with the At this time, the type wheels 2A for odd-numbered digits are already locked by the selection claws 4A for odd-numbered digits, so they do not rotate, and the desired type 201 remains aligned at the printing position 2o. The subsequent selection operation for even-numbered digits is performed in exactly the same manner as the selection of odd-numbered digits during the first rotation of the type wheel spindle 1.

However, unlike odd-numbered digits, the electromagnet 5 is not energized for the digits in which the printed characters 201 are not selected.

There is no functional problem even if the electromagnet 5 is energized and the even-numbered digit type ring 2B is locked in the same way as when selecting an odd-numbered digit. The protrusions 204 of the even numbered digit type wheels 2B come into contact, and the second numbered digit type wheels 2B are locked at that position, and at this point, the two odd numbered digit type wheels 2B, which have not selected the type 201, are locked. Since the position is approximately the same as the current position, nothing is printed, which saves energy compared to when the power is turned on.

In this manner, when the type wheel shaft 1 rotates approximately twice and stops, all the desired type characters 201 are selectively locked in the printing position 20, and the type selection process is completed.

In this state, the printing means 12 moves in the direction of the arrow and the printing paper 15
The printed characters 201 are pressed all at once via the ink ribbon 16, and the characters are printed on the printing paper 15. This is the -2 U-shaped stroke. During the printing process, the type wheel shaft 1 is stopped.

Next, the typesetting reset process will be explained. In the reset process, the type wheel shaft 1 is rotated in the direction of arrow A. Groove i of type wheel shaft 1
oi sequentially picks up the type ring springs 6 for each digit and presses the type.
Rotate wheel 2 in the direction of arrow A. Since the slope of the teeth 202 provided on the type wheel 2 rotates in the direction of arrow A while lifting the tip 401'b of the selection pawl 4b at the selection position, the selection pawl 4 is reset to the standby position σ. .

In this way, all the digits of type @2 and the selection claw 4 are reset by approximately one rotation of the type wheel shaft 1. Protrusion 20 provided on type wheel 1
4 is a function of engaging the selection pawl 4 and locking the type wheel 2 so that the type wheel 2 does not rotate further due to inertia after the type wheel shaft 1 rotates approximately one turn in the direction of arrow A and stops, and when the device is stopped. It also has the function of preventing the selection claw 4 from falling into the selection position due to disturbances such as vibration.

When this typesetting reset process is completed, one printing cycle of the apparatus is completed.

As explained above, according to the present invention, the number of expensive parts called electromagnets can be reduced to half the number of orders of magnitude, and the number of peripheral parts required for energizing the electromagnet 5 can also be halved, thereby reducing the cost. can be significantly reduced. In addition, when returning the even numbered digit selection claw 4B to the standby position between the odd number digit selection process and the even number digit selection process, the selection claw shaft 9 is moved to the even number digit selection claw 4B by the jh movement of the suction plate O. There is a possibility that a force trying to rotate the lever clockwise around the center may act, and there is a fear that the selection pawl 4B of even number digits and the selection pawl control lever 7 may come out of engagement, resulting in malfunction, but according to the present invention, this has already been explained. As shown, even number digit selection claw 4B
Since the selection pawl control lever 7 is not disengaged by the force described above, the selection pawl 4B can be reliably returned to the standby position, and there is no fear of malfunction.

Further, the movement of the selection pawl control lever 7 is simple since it only requires one reciprocating motion per printing cycle, and the cam teeth JL 17 that drive the selection pawl control lever 7 are mounted outside the frame 21. Because of this, it is possible to take a large stroke, and it is easy to manage the entire stroke. Further, when the selection claw 4 is driven by the electromagnet 5 via the suction plate 6, the tip portion 401 of the selection claw 4 has the printed character @11.
Since the type wheel 2 is received by the driving force until it enters the locus of the toothed portion 202 of No. 2 and can be engaged, the type wheel 2 can be reliably locked and there is no fear of malfunction due to external disturbances such as frictional load. In addition, the standby position of the suction plate is placed between the convex portion 6 of the suction plate 6 and the contact portion 802 of the rigid positioning plate 48 fixed to the frame 21.
01 is in contact with the electromagnet 5, and since the gap between the electromagnet 5 and the electromagnet 5 does not become larger than that, stable performance is always obtained.Also, since the selection claws 4 driven by the electromagnet 5 are always one at a time, the electromagnet 5 Since the load is small and constant, it can be designed efficiently, and its capacity can be relatively small, so costs can be reduced.

As described above, the present invention has many advantages and can provide a compact printer that is inexpensive, simple to operate, stable, and highly reliable.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the main parts of a specific example of the present invention, FIG. 2 is a schematic front view showing the arrangement of the main parts of the selection mechanism, and FIG. 6 is a perspective view of this specific example. FIG. 4 is a timing chart showing the operation of the main parts of this specific example. Subscript A
indicates a part with an odd number of digits, and the subscript B indicates a part with an even number of digits. The subscript α indicates the standby position, the subscript S indicates the selection position, and the subscript C indicates the position where the even-numbered type wheel 2B is locked during the odd-numbered digit selection process. Note that these subscripts may be omitted as appropriate unless particularly necessary. 1... Type wheel shaft 2... Type wheel 6... Type ring spring 4... Selection claw 5.71'j4 magnet
6... Suction plate 7... Selection claw control lever 8.
...Positioning plate 9...Paper selection claw shaft 10...Selection claw) Kine 11...Electromagnet mounting plate 12...Printing means 13...Paper feed roller 14...Paper presser roller 15...・Printing paper 16... Ink ribbon 1
7...Cam gear 18...Cam gear shaft 19...
・Selection pawl control lever shaft 20...Printing position or higher

Claims (1)

[Scope of Claims] A girder which is rotatably supported on a type wheel shaft via a type ring spring, and has a type on its outer periphery, a serrated tooth portion corresponding to the type on the side surface, and four parts adjacent to the toothed portion. A type wheel with a number distribution function,
a plurality of selection pawls forming a group, one of which corresponds to each of the type wheels, and engaging with the teeth or the four portions of the type wheels to lock the type wheels; Each group includes a pair It: an electromagnet that drives the selection pawl member via a suction member to engage with the teeth of the type ring to select and arrange desired characters, and the selection pawl member ( if
a selection pawl control means for periodically controlling and engaging/disengaging the four parts of the type wheel by aligning the type with each other, and striking the aligned type characters through the printing paper. In a printer configured to include a printing means for pressing and printing, and selecting all digits of the type by multiple rotations of the type wheel spindle, the selection pawl control means and the selection pawl member control the rotation of the selection pawl member. engages with a slope in the direction,
Near the start of the first revolution of the type wheel shaft, the selection pawl control means drives the selection pawl members of the digits that are not selected during the rotation, so that the type wheel is brought into a selectable state and the type is selected. Near the start of a plurality of rotations of the wheel spindle, the selection pawl member of the digit to be selected during the rotation is disengaged from the type wheel so that the digit can be selected, and the digit that can be selected during each rotation of the type wheel spindle is A small printer characterized in that the desired printed characters are selected and arranged by cooperation of the selection claw member and the electromagnet.